Fig. 2. Effect of activity on defect structure and effective elasticity.

(A) Fluorescence actin images of a passive (c = 0 μm⁻²) and active (c = 0.0015 μm⁻²) LC (l = 2 μm). The region enclosed by the box is enlarged below, and the director field (cyan lines) and defect morphology (red dashed lines) are indicated. The ratio of bend (K₃₃) to splay (K₁₁) elasticity calculated from the defect morphology are indicated in the bottom right. (B) Plot of θ versus φ corresponding to experimental images of (A) for the passive (red circles) and active (green diamonds) LC. (C) Apparent elasticity $\mathrm{\kappa }\prime ={\mathit{K}}_{33}^{\prime }/{\mathit{K}}_{11}^{\prime }$ as a function of c for experimental data. Dashed line highlights the linear scaling. (D) Director field from the simulation for both passive (α = 0) and active (α = 0.003) LC. Red arrows around the defect represent the shear flow caused by the velocity field shown in the background. (E) Apparent elasticity κ′ as a function of α obtained from simulations for extensile (black circles) and contractile (red crosses) stresses.